LAYERED DCT STILL IMAGE COMPRESSION

Motivated by Shapiro's embedded zerotree wavelet (EZW) coding and Taub man and Zakhor's layered zero coding (LZC), we propose a layered discr ete cosine transform (DCT) image compression scheme, which generates s n embedded bit stream for DCT coefficients according to their importan ce, The new method allows progressive image transmission and simplifie s the rate-control problem. In addition to these functionalities, it p rovides a substantial rate-distortion improvement over the JPEG standa rd when the bit rates become low. For example, we observe a bit rate r eduction with respect to tho JPEG Huffman and arithmetic coders by abo ut 60% and 20%, respectively, for a bit rate around 0.1 b/p.